A pure dielectric metamaterial absorber with broadband and thin thickness based on a cross-hole array structure

Abstract

In this work, a pure dielectric metamaterial absorber with broadband and thin thickness is proposed, whose structure is designed as periodic cross hole array. The pure dielectric metamaterial absorber with high permittivity is prepared by ceramic reinforced polymer composites. Compared with ones with low permittivity, the absorber with high permittivity is more sensitive to structural parameters, which means that it is easier to optimize equivalent electromagnetic parameter and achieve wide impedance matching by altering the size or shape of unit cell. The optimized metamaterial absorber exhibits the reflection loss below -10 dB in 7.93~35.76 GHz with a thickness of 3.5 mm, which shows favorable absorption property under the oblique incidence of TE polarization (±45°). Whether it is measured or simulated value, the strongest absorbing peak reaches below -45 dB, which exceeds that of most metamaterial absorber. The distributions of power loss density, electric and magnetic field are proposed to study the origin of their strong absorbing property. Multiple resonance mechanisms are developed to explain the phenomenon, including polarization relaxation of dielectric and edge effect of the cross-hole array. This work overcome the shortcoming of narrow absorbing bandwidth of dielectric. It demonstrates that the pure dielectric metamaterial absorber with high permittivity has great potential in the field of microwave absorption.

Lightweight, Compressible, and Multifunctional Organic–Inorganic Nanofibrous Aerogels for Enhanced Microwave Absorption

“…In Figure c, PCNF, Fe 7 S 8 /PCNF, and Fe 7 S 8 /PCNF@ANF demonstrated varying degrees of dielectric loss. Meanwhile, several obvious fluctuation peaks appeared in the tan δ ε curves of the three samples, indicating the existence of multiple dielectric loss. , According to numerous documents, the dielectric loss was composed of conductive loss and polarization loss, which could be explained by the Cole–Cole semicircle …”

“…Meanwhile, several obvious fluctuation peaks appeared in the tan δ ε curves of the three samples, indicating the existence of multiple dielectric loss. 54,55 According to numerous documents, the dielectric loss was composed of conductive loss and polarization loss, which could be explained by the Cole−Cole semicircle. 56 When the curve plotted by ε′ and ε″ formed a semicircle, the materials underwent the process of dielectric polarization relaxation, otherwise, conductive loss was generated.…”